A telecommunication network power system usually includes an ac-dc stage converting the power from the ac utility line to a 48V dc distribution bus and a dc-dc stage converting the 48V dc distribution bus to a plurality of voltage levels for all types of telecommunication loads. Alternatively, the 48V dc distribution bus may be converted into a low voltage bus through an isolated dc-dc converter. Furthermore, a plurality of downstream non-isolated dc-dc converters with inputs coupled to the low voltage bus may generate a variety of voltage levels in accordance with the needs of the telecommunication network power system.
Non-isolated dc-dc converters can be implemented by using different power topologies, such as buck converters, boost converters, buck-boost converters, linear regulators and/or the like. As known in the art, buck converters are widely employed to convert the intermediate bus to various voltage levels required by down stream circuits in a telecommunication system.